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Biomedical subjects

M Kishida

Publications and source records attributed to M Kishida.

At least 109 records · Page 6Linked to original sources
PubMed1986

Genetic mapping of eleven spo genes essential for ascospore formation in the fission yeast Schizosaccharomyces pombe.

Sporulation-deficient mutants of the fission yeast Schizosaccharomyces pombe were isolated from a homothallic strain mutagenized with ethyl methanesulfonate. Complementation tests defined two new genetic loci (spo19 and spo20) essential for ascospore formation, in addition to the 18 known spo loci (Bresch et al. 1968). A novel mapping procedure using random spore analysis prior to tetrad analysis allowed us to map 11 spo genes. Four genes (spo3, spo15, spo19 and spo20) were mapped on chromosome I, 6 genes (spo2, spo4, spo5, spo6, spo14 and spo18) on chromosome III and 1 gene (spo13) on chromosome III. Although there was no noticeable clustering of spo genes on the chromosomes, three pairs of linked genes (spo15-spo20, spo3-spo19 and spo2-spo18) were found.

Chromosome Mapping↗
PubMed1986

Characterization of Ac3-proteinase from the venom of Agkistrodon acutus (hundred-pace snake).

Ac3-Proteinase from the venom of Agkistrodon acutus was isolated in a homogeneous form by a previously published method. Ac3-Proteinase possessed lethal, hemorrhagic, caseinolytic, azocaseinolytic, dimethylcaseinolytic and hide powder azure hydrolytic activities. These activities were inhibited when Ac3-Proteinase was incubated with the metal chelators ethylenediaminetetraacetic acid (EDTA), ethyleneglycol-bis-(beta-aminoethyl ether)-N,N'-tetraacetic acid (EGTA), tetraethylenepentamine (TEP), 1,10-phenanthroline, phosphoramidon or beta-mercaptoethanol. The toxin also hydrolyzed the oxidized A and B chains of both insulin and fibrinogen. The cleavage sites in the oxidized B chain of insulin were identified as His(10)-Leu(11), Ala(14)-Leu(15), Tyr(16)-Leu(17) and Phe(24)-Phe(25). The A alpha chain of fibrinogen was digested first followed by hydrolysis of the B beta chain. Toxicological and biochemical properties of Ac3-Proteinase were investigated further and are reported in this paper.

Angiotensin I↗
PubMed1986

Purification and characterization of phosphodiesterase from the venom of Trimeresurus mucrosquamatus.

Phosphodiesterase was isolated from the venom of Trimeresurus mucrosquamatus from Taiwan using gel filtration on a Sephadex G-100 column, followed by anion or cation exchange chromatography. Phosphodiesterase was homogeneous as established by a single band on acrylamide gel electrophoresis and immunodiffusion. Phosphodiesterase activity was inhibited by ethylenediamine tetraacetic acid (EDTA), o-phenanthroline, thioglycolic acid or p-chloromercuribenzoate (PCMB) but not by soybean trypsin inhibitor (SBTI) or benzamidine. The molecular weight of this enzyme was determined to be approximately 140,000 and the isoelectric point was found to be pH 7.4 by isoelectric focusing with carrier ampholyte. The Michaelis constant (Km) of this enzyme for p-nitrophenyl thymidine-5'-phosphate and inhibition constant (Ki) for PCMB were found to be 5.6 X 10(-3) and 7.6 X 10(-4) M, respectively.

Amino Acids↗
PubMed1986

Reevaluation of hemorrhagic toxin, HR-I, from Agkistrodon halys blomhoffii venom: proof of proteolytic enzyme.

HR-I is a hemorrhagic toxin originally isolated from Agkistrodon halys blomhoffii (Mamushi) venom by Oshima et al. (1972). It was reported by the original investigators that it was nonproteolytic when casein was used as the substrate. HR-I was isolated again and proteolytic activity was tested using different substrates and assay methods. It is shown that HR-I is indeed a proteolytic enzyme hydrolyzing a number of peptide bonds. This present investigation suggests that more than one method should be used for proteolytic enzyme assay of hemorrhagic toxins. Toxicological and biochemical properties of HR-I were further investigated and are reported in this paper.

Amino Acids↗
PubMed1986

Comparative study of four arginine ester hydrolases, ME-1, 2, 3 and 4 from the venom of Trimeresurus mucrosquamatus (the Chinese habu snake).

Four arginine ester hydrolases, ME-1, 2, 3 and 4 from the venom of Trimeresurus mucrosquamatus had been isolated and characterized by Sugihara et al. (1980, 1981, 1982, 1983). Immunologically, ME-1, 2, 3 and 4 are identical. The four enzymes hydrolyzed Pro-Phe-Arg-MCA and z-Phe-Arg-MCA. Furthermore, ME-2 slightly hydrolyzed Boc-Val-Pro-Arg-MCA, Boc-Phe-Ser-Arg-MCA and Boc-Ile-Glu-Gly-Arg-MCA. ME-1 cleaved almost simultaneously the Arg(22)-Gly(23) and Phe(25)-Tyr(26) bond of oxidized insulin B chain. ME-2 and 3 also hydrolyzed the same bond of insulin B chain, but the activity was not as potent as ME-1. ME-4 did not cleave the substrate. The four enzymes hydrolyzed C-terminal of arginine in the biologically active peptides. Four arginine ester hydrolases showed fibrinogenolytic activity. ME-1 and 2 first cleaved B beta-chain and then A alpha-chain. On the contrary, ME-3 and 4 cleaved A alpha- and B beta-chain simultaneously. The four enzymes also hydrolyzed fibrinogen in plasma cleaving B beta- and gamma-chain and slightly digesting A alpha-chain. The various inhibitors affected TAME (tosyl-arginine-methylester) and the fibrinogen hydrolytic activity of the four enzymes. All four enzymes had fibrinolytic activity.

Amino Acid Sequence↗
PubMed1985

Isolation and characterization of hemorrhagic factors a and b from the venom of the Chinese habu snake (Trimeresurus mucrosquamatus).

Hemorrhagic factors a and b were isolated from Trimeresurus mucrosquamatus venom by Sephadex G-100, CM-Sephadex C-50 and DEAE-Sephacel column chromatographies. The hemorrhagic factors were homogeneous, as established by a single band on acrylamide gel electrophoresis, isoelectric focusing and sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis. Molecular weights of 15 000 and 27 000 were found for hemorrhagic factors a and b, respectively. Factor a possesses proteolytic activity hydrolyzing the His(10)-Leu(11), Tyr(16)-Leu(17) and Arg(22)-Gly(23) bonds of oxidized insulin B chain, whereas, factor b hydrolyzed only the Ala(14)-Leu(15) bond. Hemorrhagic activity of these hemorrhagic factors was inhibited by ethylenediaminetetraacetic acid, 1,10-phenanthroline or p-chloromercuribenzoate, but not by soybean trypsin inhibitor or diisopropyl fluorophosphate. The hemorrhagic factors were injected into the skin of the back of albino rabbits, and the minimum hemorrhagic dose of factors a and b was 1.7 and 2.3 micrograms, respectively. These purified hemorrhagic factors were not lethal at 15 micrograms/g in mice. Factor a hydrolyzed the B beta chain of fibrinogen, while factor b hydrolyzed the A alpha chain. Hemorrhagic factor a was shown to differ immunologically from factor b. Factors a and b produced systemic hemorrhage in internal organs such as the heart and stomach of mice. Moreover, factor b produced hemorrhage in the liver.

Animals↗
PubMed1985

Characterization of meiosis-deficient mutants by electron microscopy and mapping of four essential genes in the fission yeast Schizosaccharomyces pombe.

Meiosis-deficient mutants of the fission yeast Schizosaccharomyces pombe carrying mei1, mei2, mei3, mei4 and mes1 mutant alleles were characterized by electron microscopy and staining of the nucleus with 4', 6-diamidino-2-phenylindole. Zygotes of either mei1, mei2 or mei3 mutants contained one round nucleus with a single spindle pole body (SPB). These mutants were arrested before premeiotic DNA synthesis. Zygotes of mei4 mutants had one elongated nucleus containing thick electron-dense filaments (linear elements). In the mes1 mutant, the first meiotic division was completed but the SBPs did not duplicate. Modification of the SPB (outer plaque formation) was also blocked and the forespore membrane was not assembled. By haploidization, random spore and tetrad analyses, four essential genes for meiosis (mei2, mei3, mei4 and mes1) were mapped. Gene mei2 was located on chromosome I 14.2 cM distant from ura2. Gene mei3 was linked to ade7 (45.4 cM) on chromosome II. Gene mei4 was linked to cdc2 (0.6 cM) on chromosome II. Gene mes1 was linked to ura3 (25.3 cM) on chromosome I.

Ascomycota↗
PubMed1985

Characterization of mucrotoxin A from the venom of Trimeresurus mucrosquamatus (the Chinese habu snake).

Mucrotoxin A from the venom of Trimeresurus mucrosquamatus was isolated in homogeneous form by a previously published method. Mucrotoxin A did not hydrolyze casein, however, when dimethylcasein was used as a substrate, the toxin cleaved the substrate. This toxin also hydrolyzed the oxidized B chain of insulin and fibrinogen. The sites of cleavage in the oxidized B chain of insulin were identified as Ser(9)-His(10), His(10)-Leu(11), Ala(14)-Leu(15), Leu(15)-Tyr(16) and Tyr(16)-Leu(17). The toxin digested the A alpha chain of fibrinogen first, followed by hydrolysis of the B beta chain. The fact that no fibrin clot formed indicates that the sites of cleavage in the A alpha and B beta chains of fibrinogen by the toxin must be different from those cleaved by thrombin. Mucrotoxin A produced systemic hemorrhage in internal organs such as the heart and stomach.

Animals↗
PubMed1985

Comparative study of three proteinases from the venom of the Chinese habu snake (Trimeresurus mucrosquamatus).

Three immunochemically distinct proteinases (P-1, 2 and 3) devoid of hemorrhagic activity were isolated from the lyophilized venom of Trimeresurus mucrosquamatus using column chromatography on Sephadex G-100, CM-Sephadex C-50, DEAE-Sephacel, CM-Cellulose and Bio-Rex 70. By these procedures, about 7.6, 7.3 and 8.2 mg of purified P-1, 2 and 3 may be obtained from 1 g of crude venom, respectively. The purified proteinases 1-3 were homogeneous by disc electrophoresis on polyacrylamide gel at pH 4.3, isoelectric focusing and by the presence of one precipitin line on immunodiffusion. The isoelectric point of P-1 was 8.1; P-2, 9.2; P-3, 9.8. The molecular weights of proteinases 1-3 were determined to be 23,000, 23,500 and 23,000, by sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis, respectively. The purified proteinases 1-3 possessed caseinolytic and fibrinogenolytic activities. These activities were inhibited when the proteinases were incubated with the metal chelators ethylenediaminetetraacetic acid (EDTA), 1,10-phenanthroline or cysteine, but not with egg white trypsin inhibitor (EWTI) or soybean trypsin inhibitor (SBTI). P-1 cleaved the B beta-chain of fibrinogen first and then the A alpha-chain, whereas P-2 and 3 cleaved the A alpha-chain first and then the B beta-chain. However, these three proteinases did not hydrolyze the gamma-chain.

Amino Acids↗
PubMed1985

Isolation and characterization of hemorrhagic toxin g from the venom of Crotalus atrox (western diamondback rattlesnake).

Hemorrhagic toxin g (HT-g) was isolated from Crotalus atrox (western diamondback rattlesnake) venom using a five-step purification procedure to obtain approximately equal to 5.9 mg of purified HT-g from 2.0 g of crude venom. The purified toxin was homogeneous by disc electrophoresis on polyacrylamide gel at pH 8.3 and 4.3, and by isoelectric focusing. HT-g possessed lethal, hemorrhagic and proteolytic activities. These activities of toxin were inhibited by ethylenediamine-tetraacetic acid (EDTA), 1,10-phenanthroline or ethyleneglycol (beta-amino-ethyl) N,N,N',N'-tetracetic acid (EGTA), but not by cysteine or soybean trypsin inhibitor (SBTI). Its molecular weight was approximately 60,000 and the isoelectric point was 6.8. The toxin contains 516 amino acid residues. HT-g did not coagulate fibrinogen to fibrin; however, the toxin hydrolysed the A alpha-chain or B beta-chain of fibrinogen without cleaving the gamma-chain. HT-g produced only local hemorrhage in internal organs such as the intestine, heart and liver.

Amino Acids↗
PubMed1984

Isolation and biochemical characterization of hemorrhagic toxin f from the venom of Crotalus atrox (western diamondback rattlesnake).

Hemorrhagic toxin f (HT-f) was isolated from Crotalus atrox (Western Diamondback Rattlesnake) venom by a five-step purification procedure. Homogeneity was established by the formation of a single band in acrylamide gel electrophoresis, isoelectric focusing, and sodium dodecyl sulfate (SDS)-electrophoresis. HT-f has a molecular weight of 64,000 and contains 572 amino acid residues. It contains 1 mol of zinc per mol of protein. Zinc is essential for both hemorrhagic and proteolytic activities. HT-f possesses proteolytic activity hydrolyzing the Val-Asn, Gln-His, Leu-Cys, His-Leu, Ala-Leu, and Tyr-Leu bonds of oxidized insulin B chain. HT-f did not coagulate fibrinogen to fibrin, yet it did hydrolyze the gamma chain of fibrinogen without affecting either the A alpha or B beta chains. This is the first time that a hemorrhagic toxin was shown to have fibrinogenase activity. HT-f was shown to differ immunologically from other hemorrhagic toxins such as HT-a and HT-c. HT-f also possesses lethal toxicity. When zinc was removed the apo-HT-f lost its lethal toxicity. HT-f produced not only local hemorrhage in the skin and muscle, but also produced systemic hemorrhage in internal organs such as the intestine, kidney, lung, heart, and liver.

Amino Acids↗